Field devices such as radar level gauges, which are arranged to provide measurement data to a remote system, are normally configured upon installation to communicate digital data using a predefined communication protocol. Once installed, only this predefined protocol can be used. The protocol chosen will vary on the implementation.
For a field device connected to a two-wire control loop, and adapted to communicate analogue measurement data, digital data is often superimposed using Highway Addressable Remote Transducer (HART).
For a field device connected to a two wire control loop but adapted to communicate digital measurement data, the predefined protocol is often Foundation Fieldbus (FF).
Document U.S. Pat. No. 8,804,750 discloses a field device connected to a two-wire control loop, including circuitry for selectively communicating analogue measurement data or digital measurement data over the control loop. When analogue communication is used, digital HART communication is also enabled. The circuitry detects when a Fieldbus token is received, and then activates the Fieldbus communication circuitry.
Another category of field devices are not connected to a two-wire loop, but are configured to communicate on an exclusively digital interface. In such field devices, the protocol is often MODBUS.
A specific type of communication relates to configuration of a radar level gauge using a portable configuration tool. The configuration may for example relate to tank specific parameters, used by the radar level gauge in the gauging process. The digital HART protocol is commonly used for such configuration. In a situation where the radar level gauge is configured to communicate using a different digital protocol, e.g. MODBUS, it will not be possible to connect the portable configuration tool.
The prior art (e.g. U.S. Pat. No. 8,804,750) is limited to communicating on a two-wire control loop and does not provide a versatile connection of a configuration tool.